Method and apparatus for defrosting ice cubing machines



Nov. 6, 1962 J. F. BAKER 3,062,018

METHOD AND APPARATUS FOR pEERosTING ICE CUBING MACHINES med Jan. so. 1961 2 sheets-sheet 1 OOO OOO OOO INVENTOR .jf-55 /FEkf BY .mw ZM ATTORNEY 5 Nov. 6, 1962 J. F. BAKER 3,062,018

METHOD AND APPARATUS FOR DEFROSTING ICE CUBING MACHINES Filed Jan. 50, 1961 2 Sheets-Sheet 2 #cca/waive /7 /5 74 .EV/915013476@ if/7CH Z/ f@j l Aff rcamnrae ATTo'RNEYs 3,062,018 METHOD AND APPARATUS FOR DEFROSTING ICE CUBING MACHINES Jess F. Baker, 600 W. Corrington Ave., Peoria, Ill. Filed Jan. so, 196i, ser. No. 85,575 5 Claims. (Cl. 62-81) This invention relates to la method and apparatus for defrosting machines for manufacturing ice cubes, particularly for commercial use, such as for restaurants and bars, and has as its primary object the provision of an improved method and apparatus of this character which accomplishes the defrosting entirely by the use of the gas or liquid which is normally used in the freezing operation.

An additional object of the invention is the provision of such an apparatus which is entirely self contained and sealed at all times, thus avoiding any possibility of contamination of the ice from any source during either the freezing or -defrosting operation.

An additional object of the invention is the provision of such a system which employs the same coil which is used in the freezing operation for the defrosting operation, thus materially reducing the cost of installation and operation over conventional apparatus of this character.

Still another object of the invention is the provision of such a method and apparatus `which materially reduces the time for defrosting, thus increasing the capacity of the apparatus over a given period of time.

As conductive to a clearer understanding of this invention, it may here be pointed out that the conventional method of manufacturing ice cubes for restaurant and bar use employs a freezing unit comprised of a plate containing cup-shaped indentations surrounded by `a refrigerating coil. In operation a rotation spray arm beneath these cup-shaped indentations sprays water upward into them, the water being frozen in consecutive layers until Ithe normal ice unit or cube adapted to be contained in a water glass for 'a drink is fully formed. At this time a heating element is put into operation which defrosts the outer surface of the ice cube, permitting it to drop into a reservoir available for use.

The defrosting is presently effected by several methods. One of these methods comprises the use of `an electrical heating coil in the freezing unit which raises the ternperature of the cup itself to a point at which the ice cube is released.

The second method employs the use of hot water flowing across a platen at the top of the freezing unit, which heats the unit to an extent sufficient to free the cube from the cup container.

In still other apparatus a second coil is employed in the freezing unit, completely separate from the refrigerating coil, and a hot gas is blown through this auxiliary coil thus heating the freezing unit to a point where defrosting occurs.

In order to free the ice cube it is necessary in every case that means be provided for the introduction of air at the top of the cup to avoid the formation of a vacuum and the sticking of the frozen cube in the cup. This is normally accomplished by perforating the top of a cup providing openings through which air can pass when the ice cube itself falls. This requirement renders the hot water method unsatisfactory, since by its very nature a certain amount of the water used in defrosting contacts the ice cube before it drops, thus making contamination possible. The double coil method for the introduction of hot gases requires a considerably more elaborate apparatus, requiring, as it does, a double coil with a corresponding increase in initial expenditure, while the method employing the electrical heating coil entails materially increased operating expense through the use of electric power.

'i att t 3,062,018 Patented Nov. 6, 1962 An important object of the present invention is, therefore, the elimination of all of the above-mentioned objections as well as others since, in the instant invention the heating operation is achieved by substantially the identical apparatus employed in initially freezing the cube, and the identical freezing element, which may be either gas or liquid, contained in a sealed coil, is employed in the defrosting operation. Since this material is contained in a sealed coil, the possibility of contamination of any sort is obviated, and since the same coil is employed for both freezing and defrosting, there is no material increase in construction costs. Furthermore, .since the surplus heat generated by the compressor itself is employed in the defrosting operation, there is no material increase in operating expense.

Still another object of this invention is the provision of an apparatus of this nature which is sturdy and durable in construction, reliable and eicient in operation, and relatively simple and inexpensive to manufacture, install, and utilize.

Other objects will in part be obvious and in part be pointed out as the description of the invention proceeds and shown in the -accompanying drawings which disclose a preferred form of apparatus for achieving the method of the instant invention.

In the drawings:

FIGURE 1 is a schematic view of one form of apparatus constructed in accordance with the instant invention shown during the freezing cycle; and

FIGURE 2 is a view similar to FIG. l but disclosing the -apparatus during the defrosting operation.

Similar reference characters refer to similar parts throughout the several views of the drawing.

Having reference now to the drawings in detail, there is generally indicated at 10` a refrigerator or freezing receptacle, of any desired conventional type, and which may, if desired, be insulated.

Adjacent the top of compartment or receptacle 10, there is provided a plate 11, which is divided by a series of vertically positioned baffles 13 into a plurality of cups of the size of a conventional ice cube, the cups opening downwardly.

The refrigerating unit is surrounded by Ka `coil 14, provided with an inlet line 15, and an outlet line 16. The outlet line 16 extends to an accumulator tank 17 which is surrounded by a coil 18, from which coil a line 19, comprising the refrigerant line, extends to the inlet 15 of the refrigerating coil.

Below the refrigerating cups 13 there is positioned an arm 20 which is adapted to be rotated in any conventional manner, and which is provided with a plurality of upwardly directed spray outlets Z1, from which water under pressure is sprayed into the cups formed by the baflies 13, wherein, when the refrigerating process is in operation it freezes in successive layers to form ice cubes.

Pipe 20 is supplied with water from an inlet 22, which extends to a sump tank 23. A float 24 in tank 23 controls an inlet valve 25 which in turn controls the admission of water through an inlet 26. The usual sump tank 27 is provided as is a sump drain 2S controlled' by a valve 29. A plate 30 in the bottom of tank or receptacle 10 is inclined toward an outlet 31, which communicates through a passage 32 with the sump tank, for the return of water emanating from the nozzle 21 which is not frozen in the cups 13.

An oppositely inclined perforated baffle 35 is positioned beneath the pipe or tube 20, and is adapted to deflect the ice cubes, when they fall from the cups during the defrosting operation, in a manner to be more fully described hereinafter, toward an access door 36, through which the cubes after freezing may be removed from the apparatus.

Refrigerant is supplied to the coil 18 through a refrigerant tube 40, it being noted that the tube 40 is of materially reduced diameter, as is the coil 18 in the pipe 19, as compared to the refrigerant coil 14 so that the refrigerant, which passes through tube 4i) in the form of a relatively hot liquid, is permitted to expand in the coil 14 to cause refrigeration in a known manner. Tube 40 extends from a receiver 41, in which the hot refrigerant is stored, the receiver being supplied through a line 42 which extends from a condenser 43, the latter being provided with a fan 44 and a fan control 45. Refrigerant is supplied to the condenser through a line 46 which extends from a coil 47 positioned about a second accumulator 48, the coil being provided with an inlet 49 from a compressor 50. Compressor 50 is supplied through a line 51, which extends to the accumulator 48, the latter being filled by means of a suction line 52 which extends from the interior of the rst accumulator 17.

The apparatus previously described is in many respects conventional and comprises per se no part of the instant invention, since the refrigerating cycle for devices of this sort is Well known and may be varied in accordance with specific conditions. The essence of the instant invention, however, comprises the introduction of a hot liquid line 55 which extends from an inlet 56 in the inlet portion 15 of coil 14 through a solenoid valve 57 and a line 58 to the bottom of receiver 41. The line 55 is of substantially the same diameter as the expansion coil 14 so that when hot liquid is passed through the line 55 from the receiver 41, no expansion occurs, and the hot liquid circulates in its heated form through the coil 14. This obviously effects a melting of the surface of the ice cubes adjacent the partitions 13, and results in the cubes falling by gravity, after they have been `freed from the cup-shaped indentations onto the bafiie or partition 3S, where they accumulate adjacent the door 36 in a condition to be removed for use.

The solenoid valve 51 is automatic in its operation, and is controlled by a clock mechanism 60 through wires 61, the clock being controlled in turn by a thermostatic switch 62 through lines 63, current being supplied in a conventional manner through wiring 64.

While the apparatus may obviously be made in any desired size or shape, and of any suitable materials, the relationship of the size of the lines has been found to be important. In the illustrative embodiment of the invention, the line 40, which is the refrigerant tube, is approximately 1/16 inch in diameter, while the hot liquid line 55 is approximately 3/8 inch in diameter, as are all the other component lines of the apparatus, This relationship of cross-sectional area should -be maintained, at least approximately, regardless of the actual dimensions of the several tubes and pipes.

In the use and operation of the device, refrigerant travels from receiver 41 through line 40, coil 18, pipe 19, inlet and about the evaporator coil 14, cooling the cups defined by the partitions 13, and Water is sprayed from the pipe upwardly into the cups and freezes in layers until the ice cubes are frozen all in conventional manner. Liquid returning from the coil passes through pipe 16 into accumulator 17 and thence through return line SZ into the accumulator 48, from which the refrigerant passes through line 51 to compressor 50, and thence through line `49, coil 47 and line 46 to the condenser. The condensed and consequently heated liquid then flows from the condenser through line 42 back to the top of receiver 41, the cycle continuing for a predetermined time in accordance with the size and operating characteristics of the apparatus until the cubes are completely formed.

When the cubes have been completely frozen the thermostatic switch 62 is operated by the known falling of temperature and rise of pressure in the freezing unit when the 4freezing action has been completed, and actuates through wire 63, the clock 60. Clock 60 in turn actuates the solenoid valve 57. The opening of valve 57 Cil opens the line 58 into the line 40, and draws hot liquid from the receiver 41.

Firstly, by lowering the pressure of tank or receiver 41 the height of liquid refrigerant is released below the outlet to the tube 40. The flow of liquid through the refrigerant tube `40 is thus cut off, and all refrigerating action in the coil 11 is stopped. Since the line 40 is the same size as the tubes in the freezing unit, the introduction of the hot liquid through the line 40 automatically iills the entire space in which the refrigerant normally expands with the hot liquid thus rendering the freezing action caused by the expansion of the liquid impossible.

The second result is that upon the introduction of hot refrigerant through the line 40 directly into the freezing unit through opening 56 and 15 the temperature of the unit is raised to a point Where the surface layer of the ice cubes is melted permitting the cubes to drop by gravity onto the partition 35 of the reservoir.

The required time for such defrosting is predetermined, it being pointed out that in a unit of this size the defrosting time is approximately three minutes, and the clock 60 is so arranged as to maintain the valve 57 in open condition for this length of time.

When the clock 60 operates to close the solenoid valve S7, compressor immediately forces liquid into the receiver 41 until such liquid passes the level of the inlet of refrigerant tube 46, at which time the liquid flows through the line 4t) and the refrigerating cycle is again inaugurated.

From the Aforegoing it will now be seen that there is herein provided an improved method and apparatus for defrosting ice cubing machines of the character described, which accomplishes all the objects of this invention, and others, including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative, and not in a limiting sense.

I claim:

1. A method of defrosting commercial ice cube making apparatus of the type including a receiver tank, an

inverted refrigerating unit, means for spraying water to be frozen upwardly into said unit, a refrigerating coil connected to said receiver tank by means of a line of less diameter than said coil, an accumulator connected to said coil, a return line from said accumulator through a compressor and a condenser to said receiver tank, comprising the sequential steps of discontinuing passage of refrigerant through said line of less diameter after said refrigerating unit has frozen the cubes, and conducting hot liquid refrigerant directly from said receiver tank to said coil through a tube of a. diameter substantially equal to the diameter of the coil, preventing refrigeration through expansion of said liquid and thereby melting the surface layer of said cubes, and permitting the same to fall by gravity from said refrigerating unit.

2. A method of defrosting commercial ice cube making apparatus of the type including a receiver tank, an inverted refrigerating unit, means for spraying Water to be frozen upwardly into said unit, a refrigerating coil connected to said receiver tank by means of a line of less diameter than said coil, an accumulator connected to said coil, a return line from said accumulator through a compressor and a condenser to said receiver tank, comprising the sequential steps of discontinuing passage of refrigerant through said line of less diameter after said refrigerating unit has frozen the cubes, and conducting hot liquid refrigerant directly from said receiver tank to said coil through a tube of a diameter substantially equal to the diameter of the coil, preventing refrigeration through expansion of said liquid and thereby melting the surface layer of said cubes, and permitting the same to fall by gravity from said refrigerating unit, continuing the ow of said hot liquid refrigerant for a predetermined period, discontinuing the flow of liquid through said last-mentioned line, and recirculating the fluid through said line of lesser diameter to resume the -refrigerating cycle.

3. Apparatus for defrosting commercial ice cube making machines of the type including a receiver tank, an inverted refrigerating unit, means for spraying water to be frozen upwardly into said refrigerating unit, a refrigerating coil connected to said tank by means of a line of less diameter than said coil surrounding said refrigerating unit, an accumulator connec-ted to said coil, a return line from said accumulator through a compressor and a condenser to said receiver tank, said apparatus including a line of a diameter substantially equal to that of said refrigeratnig coil extending from the bottom of said receiver tank directly to said coil, means for opening said last-mentioned line after the ice cubes are frozen in said refrigerating unit to conduct hot liquid refrigerant to said evaporator, and means for reclosing said last-mentioned line after a predetermined period.

4. Apparatus for defrosting commercial ice cube making machines of the ty-pe including a receiver tank, an inverted refrigerating unit, means for spraying water to -be frozen upwardly into said refrigerating unit, a refrigerating coil connected to said tank by means of a line of less diameter than said coil surrounding said refrigerating unit, an accumulator connected to said coil, a return line from said accumulator through a compressor and a condenser to said receiver tank, said apparatus including a line of a diameter substantially equal to that of said refrigerating coil extending from the bottom of said receiver tank directly to said coil, means for opening said lastmentioned line after the ice cubes are frozen `in said refrigerator unit to conduct hot liquid refrigerant to said evaporator, means for reclosing said last-mentioned line after a predetermined period, said means for opening and reclosing said line including a valve in said line of substantially equal diameter, and thcrmostatic means associated with said refrigerating unit for controlling said valve.

5. Apparatus for defrosting commercial ice cube making machines of the type including a receiver tank, an inverted refrigerating unit, means for spraying water to be frozen upwardly into said refrigerating unit, a refrigerating coil connected to said tank by means of a line of less diameter than said coil surrounding said refrigerating unit, 4an accumulator connected to said coil, a return line from said accumulator through a compressor and a condenser to said receiver tank, said appara-tus including a line of a diameter substantially equal to that of said refrigerating coil extending from the ybottom of said receiver tank directly to said coil, means for opening said last-mentioned line after `the ice cubes are frozen in said refrigerator unit to conduct hot liquid refrigerant to said evaporator, means for reclosing said last-mentioned line after a predetermined period, said means for opening and reclosing said line including a valve in said line of substantially equal diameter, thermostatic means associated with said refrigerating unit for controlling said valve, and clock means actuated by said thermostatic means for controlling the duration of the opening of said valve.

References Cited in the le of this patent UNITED STATES PATENTS 2,405,272 Smith Aug. 6, 1946 2,645,095 Ploeger July 14, 1953 2,674,858 Magnuson Apr. 13, 1954 2,722,110 Denzer Nov. 1, 1955 2,740,265 Bayston Apr. 3, 1956 2,741,096 Fitzner Apr. 10, 1956 2,821,070 Watt Ian. 28, 1958 2,866,322 lMuli'ly Dec. 30, 1958 2,867,093 Simmons Ian. 6, 1959 2,974,498 Ehrenf-reund Mar. 14, 1961 2,978,882 Bollefer Apr. l1, 1961 

